Roofing material.



. grass has good tensile str 1T0 Drawing.

a citizen of the United States, residin nnnnnnr manhunt, or raw ronx, n. Y.

ROOFING MATERIAL.

To all whom it may concern:

Be it known that I, HERBERT ABRAHAM, at

the city, county, and State of New ork,

have invented certain new and useful Improvements in Roofing Materials, of which the following is a specification.

My invention relates to waterproof roofing materials of'the kind known commonly as flexible prepared roofings, also prepared roofing shingles, which consist of a felted fabric either saturated, or saturated and coated, with bituminous materials. The invention applies more particularly to the.

felted fabric used in the manufacture of such roofings. I

According to'my invention I use certain varieties of marine plants of a fibrous nature, particularly sea grass-or ,eelgrass of the Naiadccew family, for the production of the fibrous felt. Sea grass grows in both fresh and salt water, and can be readily andcheaply obtained inlarge quantities. It resists decay to a remarkable degree when exposed to the elements, and also withstands fire in that it. does not readily ignite in its air-dry state. v

I have found that felt containing sea ength and porosity, and is much cheaper to manufacture than felt made from cotton and lwoolen rags, jute or other ligneous fibers or paper "111p. I

In practising my-inventlon, I dismtegrate the rag fibers in a bea machine in thqusual manner. To the fib ous mass or pulp consist' of the-rag fibers suspended in water,-

I have obtaine very satisfactory results by using a mixture containing approximately- 25% of sea grass based on the weight. The. sea grass fibers can either added alone or with a suitable quantity of waste papers. The mixture is then beaten to bring it to a properly shredded condition.

The stock is then run into sheets .e' the 1 desired size and thickets on a felt machine common to the felt and open industries, and the sheets thus form are dried. This felt is subsequently either impregnated with tar to form thearticle of com- Specification of Letters Patent.

. add a quantity of, the; sea. grass in its raw or natural state, that iswithout being revlously treated chemically.

Patented May 22, 1917.

Application filed February 27, 1917. Serial No. 151,179.

merce known as tarred felt, or else with asphalt to form what 'isknown commerciallyas asphalt saturated felt. The felt may similarly be impregnated with a soft bituminous material and then surfaced with a bituminous material of a harder conslstency to form what is known commercially as flexible prepared roofing, or, it may be further treated with particles of crushed slate or other mineral material em bedded on the surface and cut into smaller units to form what is known commercially as prepared roofing shingles.

It has'been customary to add waste papers (composed of either mechanically ground or chemically treatedpaper. fibers) to the ragfibers, either to cheapen-or else to suitably harden the latter. In practice, however, it has not been found-possible to use more than about half paper fibers to half rag fibers based on their dry Weight, without detracting from the porosity or pliability of the felt. I. have found that the use of sea ass fibers in conjunction with the paper bers will overcome these tendencies, andwill produce a sheet which on account. of

its porosity will saturate well with the hi tummous material, and at the same time will present greater pliability than if the paper stock alone were used. Thus for example I have obtained very good results by using a mixture composed of 25% of sea grass, 40% of pa er stock, and 35% of rag stock based on t eirdry weights, but it is not to.

be understood that I limit myself to these specific proportions, as even larger quantitles of the sea-grass can be used in case it is so desired.

.The felted fabric herein described is intended primarily for use in the manufacture of prepared roofings, including shingles, but it is net-'to'be understood that I limit myself to that particular use of the material, as it may be used for other pur- What I claim as my invention and deslre to secure by Letters Patent is:

1. A prepared roofing comprising a felt tummous su ces.

2. A pre ared comprising a felt I composedo amixture ofragsandsea grass 1 contaimng sea grass waterproofed with biw t fibers 'waterproofed with bituminous subwhich have not been treated chemically, stances. with rag fibers.

10 3. A prepared roofing comprising a felt 5. A felted sheet formed of a beaten pulp composed of a mlxture of rags, paper and containing sea grass fibers which have not 5 sea grass fibers waterproofed with bfitubeen treated chemically, with rag and paper minous substances. fibers.

4:. A felted sheet formed of a beaten pulp containing a mixture of sea grass fibers HERBERT ABRAHAM. 

